Mixing nozzle



June 14, 1949., r

R. M. DOULL MIXING NOZZLE Filed April l0, 1946 2 Sheets-Sheet l INVENTOR R.M.DOULL Wmn ATTORN EYS R. M. DOULL MIXING NOZZLE .Wune 14, 1949.

Filed April 1o, 1946 v uri U w Rm au Jv-,H

INVENTOR RJVLDOULL of nozzle section 5 and the relatively short end portion l2 of nozzle section 6. This intermediate bend portion of the nozzle passage includes a central zone C of maximum cross sectional area, and end zones D and D of gradually diminishing cross sectional area toward the ends of the nozzle. The end zone D diminishes in area toward and merges with a cylindrical inlet zone E extending to the inlet end A of the nozzle. The zone D diminishes in area toward and merges with a cylindrical discharge zone F extending to the discharge end B of the nozzle in alignment with the inlet zone E.

The sand and cement are delivered to the inlet zone E of the nozzle passage through a conventional water ring I6 coupling the inlet end of the nozzle to the sand and cement supply hose I'I through which the sand and cement are pneumatically propelled at high velocity. The water ring is provided with the usual water passages !8 through which water is added to the sand and cement entering the nozzle inlet zone E. As the stream of material passes from inlet zone E, through the zones D, C and D', to the outlet zone F, it is caused to change its direction of flow. The stream of material is also permitted to expand during its passage through zones D and C but is contracted during its passage through zone D to outlet Zone F.

The turbulence resulting from the change in direction of flow of the stream as it travels from the inlet to the discharge end of the nozzle passage causes the particles of the stream to be subjected to a rolling and mixing action which enables the particles to be more intimately mixed and also ensures better hydration of the cementitious material prior to its discharge from the nozzle.

The manner in which the intermediate bend portion of the nozzle flow passage is Varied in cross section in rela-tion to the flow of material through the nozzle permits the air carrying the sand and cement particles to expand shortly after it enters the nozzle and to be compressed again before it leaves the nozzle. The net result is a thorough mechanical mixing by reason of the turbulence set up in the stream of material by the change in direction and the further agitation caused by rapidly expanding and then contracting the air carrying the aggregate particles and water toward the discharge end of the nozzle. The ultimate advantage obtained is that the stream of material leaving the nozzle exhibits a substantially reduced tendency to spread and the particles of material are more intimately mixed so that greater cohesion between the particles is obtained and this, in turn, increases the adhesion between the particles and the surfaces against which they are projecting.

The Water ring i 6 is screwed onto a threaded collar formed by mating externally threaded portions 12a and Ila of the nozzle sections 5 and 6.

The semi-cylindrical end portion I2 of each nozzle section has the same radius as the opposing semi-cylindrical portion il of the companion nozzle section. Consequently, the inlet zone E formed by and between the opposing cylindrical end portions Il and I2 located at the inlet end of the nozzle is of greater diameter compared with the outlet zone F formed by and between the opposing cylindrical portions Il and I2 at the discharge end of the nozzle.

The mixing passage defining surfaces of the metal nozzle sections are protected by a rubber lining 20, preferably moulded in one piece shaped to t the nozzle sections.

I claim:

1. A mixing nozzle of the kind described comprising two full length casing sections formed with straight longitudinal side edges butted together, each section comprising end portions of unequal length and an intermediate portion having a maximum depth greater than the maximum depth of the end portions, said sections being butted together with the shorter end portion of each section opposed to the longer end portion of the companion section and with the said intermediate portions of the sections staggered longitudinally of the nozzle.

2. A mixing nozzle as set forth in claim 1, in which the end portions of each section are semi-circular in cross section and in which the intermediate portion of each section is substantially U-shaped in cross section.

3. A mixing nozzle as set forth in claim 1, in which the opposite end portions of each section are semi-circular in cross section and in which the shorter end portion of one section has a greater radius than the longer end portion While the shorter end portion of the companion section has a smaller radius than the longer end portion, the radius of each end portion of each section being the same as that of the opposing end portion of the companion section.

4. A mixing nozzle as set forth in claim 1 in which the intermediate portion of each section gradually diminishes in depth toward the end portions.

5. A mixing nozzle as set forth in claim l, in which the end portions of each section are semi-circular in cross section and are aligned with each other and in which the intermediate portion of each section is substantially U-shaped in cross section and gradually diminishes in depth toward the end portions.

ROBERT M. DOULL.

REFERENCES CITED The following referenlces are of record in the lle of this patent:

UNITED STATES PATENTS Number Name Date 1,507,773 Hamm Sept. 9, 1924 80 1,562,194 Schaefer Nov. 17, 1925 1,784,503 Swann Dec. 9, 1930 2,025,974 Fritz Dec. 31, 1935 FOREIGN PATENTS Number Country Date 518,776 Great Britain Mar. 7, 1940 

